The use of LEDs in general lighting is becoming more common. LED-based illumination devices are often electrically configured as strings of LEDs in series with the strings arranged in parallel. Thus, multiple LEDs are coupled in series to form an LED string and multiple LED strings are coupled in parallel to a common current source. Without compensation, the current supplied to each LED string depends on the forward voltage characteristic of each LED string. For example, if a first LED string has a significantly lower forward voltage than a second LED string, more current will flow through the first LED string than the second LED string. Consequently, one LED string may be operating below its full light generating potential while another LED string may be operating at current levels that overdrive the LEDs and reduce their lifetime, which is undesireable from the standpoint of efficiency and reliability.